The present invention relates generally to navigation systems which calculate the position of the user using a GPS link, and more specifically to a GPS navigation system tailored for use by the visually impaired.
Finding one""s exact location in an unfamiliar city has presented a problem. Discovering a location is even more challenging for the visually impaired. The visual clues used by sighted individuals in an unfamiliar place are useless to the blind pedestrian.
To provide the military with a location determination system, the U.S. Department of Defense (DoD) has devised a system that can very accurately locate any point in three-dimensional space. This system is known as the global positioning system (GPS).
There are twenty-four non-geosynchronous satellites circling the earth as part of a $12 billion DoD location determination system. An accurate location can be determined by measuring the distance to at least three satellites. Since the signals produced by the satellites are not classified by the military, civilian companies have produced portable GPS receivers for determining exact locations on the earth. A GPS receiver can pinpoint a location on the earth to within about 100 meters.
This invention relates to map positioning hardware for continuously establishing a user""s geographical position and providing progressive vectors/directions to/within selected destinations or facilities by voice output and/or Braille map displays. Specifically, this invention is a reduced weight, extremely accurate global positioning active navigation system for both visually handicapped and DoD/police users. This device phonetically describes user""s geographical position and provides phonic and/or braille vectors to/within selected destinations. It differs from ALL other GPS systems by its incorporation of digital cellular telephone link to a city/regional base station. The significant advantage is realized by: Marked weight reduction and bulk of the hand-held unit because GPS computations, map database, and voice recognition hardware and files are all relocated from hand-held unit to the base station; and centimeter system accuracy and reduced hardware costs because the entire network (hand-held units and base station) rely upon the base station""s single survey-grade GPS system which has proven accuracy of 2-3 centimeters. With the survey-grade GPS system centrally located, redundancy of having one GPS computer per hand-held unit is eliminated.
The ability to accurately navigate is severely challenged by blindness and/or darkness, especially when the user is not familiar with his/her surroundings/environment. The advent of GPS systems such as Magellan Corporation""s NeverLost automotive GPS system used by Hertz Rental Corporation has provided the foundation of this invention. Improving upon and applying this technology to the blind expands the world of travel freedom by allowing the blind to significantly expand the distance they can comfortably and safely traverse. The military, specifically ground forces whose tactics require light weight/extremely accurate navigation tools to operate in an urban environment will especially benefit from this invention while performing operations in strange/unknown urban surroundings. The ramifications of positional disorientation and/or inability to map read and navigate roads and within buildings, while leading combatants/equipment have proven to cause delays and loss of tactical advantage and initiative. This invention improves upon Magellan Corporation""s NeverLost automotive GPS navigation system to the blind and military/police users. NeverLost correlates GPS coordinates with mapped locations and provides real-time directions/steering to selected addresses. Inventions such as U.S. Pat. No. 5,470,233 claim to capture the ability to keep the visually handicapped user informed of his/her GPS derived location, but it and others fail in their designs/claims to take the process to the next logical step of dramatically improving accuracy, significantly reducing weight and creating the ability to blindly navigate city streets and within major buildings/facilities. Therefore, applying centimeter accurate GPS system to create an active navigation system for the visually handicapped using digital cellular telephone links to a central base station is the essence of AF Invention AFB0017.
One of the best existing systems is described in the U.S. Pat. No. 5,470,223 issued to Fruchterman, which is incorporated herein by reference and which describes a GPS that helps a blind pedestrian navigate through a city. This system uses the DoD Global Positioning System and a Differential GPS receiver to determine a pedestrian""s longitude and latitude. Once these coordinates have been determined, they are correlated with a computerized map database. The map database holds the names and coordinates of specific locations, such as intersections, in a particular region. The system of the Fruchterman invention retrieves the names of locations from the map database that are near the pedestrian. These names are then output to a voice synthesizer.
Other prior art systems are described in the following U.S. Patents, which are incorporated herein by reference:
U.S. Pat. No. 5,343,399 issued to Yokoyama et al;
U.S. Pat. No. 5,345,388 issued to Kashiwazaki;
U.S. Pat. No. 5,371,497 issued to Nimura et al;
U.S. Pat. No. 4,694,494 issue d to Woolfson;
U.S. Pat. No. 4,731,613 issued to Endo et al;
U.S. Pat. No. 5,032,836 issued to Ono et al;
U.S. Pat. No. 5,117,363 issued to Akiyama et al;
U.S. Pat. No. 5,119,301 issued to Shimizu et al;
U.S. Pat. No. 5,189,430 issued to Yano et al;
U.S. Pat. No. 5,225,842 issued to Brown et al.
While Fruchterman is excellent, it uses a voice system where city noise might obscure important information. The present invention uses a Braille display such as shown in the following patents, which are incorporated herein by reference:
U.S. Pat. No. 5,685,721, Nov. 11, 1997, Refreshable Braille-cell display implemented with shape memory alloys, Decker, Lawrence H.,
U.S. Pat. No. 5,580,251, Dec. 3, 1996, Electronic refreshable tactile display for Braille text and graphics, Gilkes, Alan M.,
U.S. Pat. No. 5,453,012, Sep. 26, 1995, Braille display, Hudecek,
U.S. Pat. No. 5,293,464, Mar. 8, 1994, Braille reading display terminal device, Hirano,
U.S. Pat. No. 5,244,288, Sep. 14, 1993, Method and apparatus for Braille display of information from CRT screen, Nagoaka.
Invention is a hand-held GPS for use by the blind and special forces working in urban areas under conditions of total darkness. Unit operates in similar fashion as typical GPS"" with the main differences being in application and display. Application in total darkness and for use by blind is completely different from existing applications and is made possible by use of an active Braille display. The Braille display can function/present information in at least three modes: First and primary mode is audio directions; second is through basic Braille vectors on hand-held display; and third is a complex Braille topographic display on the hand-held display. Individual city, street, address, and major building layouts are programmed into the system""s database. To ensure the highest accuracy, each city transmits a differential GPS signal that works in concert with satellite GPS signals. The user types in desired address or service (such as closest toilet, security, emergency exit, or telephone) via Braille keyboard. Database in concert with GPS signal provide user present position and vectors to selected location. Using audio vectors, voice database provides xe2x80x9cturn left, turn right, distance to intersections, roads and intersections, user""s current heading, and time to selected destination. The basic Braille vectors mode provides the user with Braille vector providing both magnitude and direction that is felt by the user. As the user approaches a turnpoint, the vector becomes shorter and shorter until the turnpoint or destination is reached. When the selected destination is reached the single point remaining from the vector pulses to let the user know he/she has arrived. The topographic Braille display is composed of a system similar to a CRT, but instead, the hard glass display is replaced with a soft iron oxide coated mylar type membrane. Details that would normally be projected/seen on the typical CRT are now three-dimensionalized against the flexible display membrane and can now be felt by the blind""s Braille trained hands. In this manner, the xe2x80x9cbig picturexe2x80x9d is provided to the user in the form of a map each can use to xe2x80x9cfeelxe2x80x9d his/her way from origin to destination. Navigational safety functions that could be incorporated are audio and/or Braille warnings as user approaches streets.
This invention includes off the shelf software that runs a GPS navigation system for use by the visually impaired and/or DoD/police that accurately determines user geographic position and provides verbal and/or Braille vectors/directions to selected location(s). It is a hand-held GPS system for use by the blind and Special Forces/police working in urban areas/buildings requiring light weight/extremely accurate navigation capability. Unit operated in similar fashion as typical GPS hand held systems, with the main differences being in application, displays, and use of a base server (FIGS. 2 and 3). Application in total darkness and for use by blind is completely different from existing applications and is made possible by use of an active braille display (FIGS. 4 and 6). The Braille displays can function/present directional navigation vectors in at least three modes: First and primary mode is audio vectors; second is through basic Braille command vectors presented on the hand-held display (FIG. 4); and third is a complex Braille topographic display depicted on the hand-held display (FIG. 6). Individual city, street, address, and internal layouts of major buildings are programmed into the system""s base station map database. To ensure the highest accuracy, the base station incorporates a survey-grade GPS system having a proven accuracy of 2-3 centimeters. The user enters desired address, or location (such as closest toilet, security, emergency medical, emergency exit, or telephone) into the system by typing or speaking (using voice recognition software interface). Invention in concert with map database and GPS signals provides user present position and vectors to the desired location through audio vector commands such as xe2x80x9cturn left, turn right, distance to intersections, roads, stairways, etc.xe2x80x9d The basic braille vectors mode (FIG. 4) provides the user with braille vectors providing both distance and direction that the user feels with hand/fingers. The topographic braille display (FIG. 6) utilizes a modified cathode ray tube to present a moving map three dimensional topographic map of user present position and layout of path which lies in front of vector path to destination. Invention can incorporate enhanced features such as cellular telephone; weather forecast radio; and/or traffic light signal information.